A travel-time path calibration strategy for back-projection of large earthquakes and its application and validation through the segmented super-shear rupture imaging of the 2002 Mw 7.9 Denali earthquake
We investigate the impact of source-side 3D velocity structure on teleseismic travel-time in back projection (BP) analysis of large earthquakes. We use travel-time data of teleseismic events recorded by the Hi-Net array to reveal how travel-time errors vary with source location. In a source area of...
| Main Authors: | , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2023
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| Subjects: | |
| Online Access: | https://hdl.handle.net/10356/165584 |
| _version_ | 1811696034496118784 |
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| author | Zeng, Hongyu Wei, Shengji Rosakis, Ares |
| author2 | Asian School of the Environment |
| author_facet | Asian School of the Environment Zeng, Hongyu Wei, Shengji Rosakis, Ares |
| author_sort | Zeng, Hongyu |
| collection | NTU |
| description | We investigate the impact of source-side 3D velocity structure on teleseismic travel-time in back projection (BP) analysis of large earthquakes. We use travel-time data of teleseismic events recorded by the Hi-Net array to reveal how travel-time errors vary with source location. In a source area of a few hundred km, where travel-time error varies dominantly linearly, we propose a new interpolation scheme using earthquakes located around the mainshock rupture to calibrate the travel-time error, and validate it by relocating inland M > 5.0 earthquakes in central Japan. We then apply it to image the rupture of the 2002 Denali earthquake. The calibrated BP result shows that most of the high-frequency radiators are <15 km away from the surface rupture trace. The new result reveals that the rupture started on the Susitna Glacier Fault with a speed of ∼1.4 km/s, then propagated onto the Denali Fault and accelerated to a super-shear speed approaching the crustal P-wave velocity at approximately 30 km. The location of super-shear transition and rupture speed in BP are highly consistent with that inferred from the timing and amplitude ratio of the super-shear and trailing Rayleigh pulses observed on the near fault PS-10 station. Subsequently, the rupture stagnated for ∼15 s before penetrating through the largest asperity, re-accelerated to a speed of ∼5.2 km/s and continued on the last 60 km of the Denali fault and part of Totschunda Fault. This application shows the great potential of the new BP calibration strategy to refine the rupture imaging of other mega-earthquakes. |
| first_indexed | 2024-10-01T07:32:57Z |
| format | Journal Article |
| id | ntu-10356/165584 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T07:32:57Z |
| publishDate | 2023 |
| record_format | dspace |
| spelling | ntu-10356/1655842023-04-03T15:31:47Z A travel-time path calibration strategy for back-projection of large earthquakes and its application and validation through the segmented super-shear rupture imaging of the 2002 Mw 7.9 Denali earthquake Zeng, Hongyu Wei, Shengji Rosakis, Ares Asian School of the Environment Earth Observatory of Singapore Science::Geology Back Projection Denali Earthquake We investigate the impact of source-side 3D velocity structure on teleseismic travel-time in back projection (BP) analysis of large earthquakes. We use travel-time data of teleseismic events recorded by the Hi-Net array to reveal how travel-time errors vary with source location. In a source area of a few hundred km, where travel-time error varies dominantly linearly, we propose a new interpolation scheme using earthquakes located around the mainshock rupture to calibrate the travel-time error, and validate it by relocating inland M > 5.0 earthquakes in central Japan. We then apply it to image the rupture of the 2002 Denali earthquake. The calibrated BP result shows that most of the high-frequency radiators are <15 km away from the surface rupture trace. The new result reveals that the rupture started on the Susitna Glacier Fault with a speed of ∼1.4 km/s, then propagated onto the Denali Fault and accelerated to a super-shear speed approaching the crustal P-wave velocity at approximately 30 km. The location of super-shear transition and rupture speed in BP are highly consistent with that inferred from the timing and amplitude ratio of the super-shear and trailing Rayleigh pulses observed on the near fault PS-10 station. Subsequently, the rupture stagnated for ∼15 s before penetrating through the largest asperity, re-accelerated to a speed of ∼5.2 km/s and continued on the last 60 km of the Denali fault and part of Totschunda Fault. This application shows the great potential of the new BP calibration strategy to refine the rupture imaging of other mega-earthquakes. Ministry of Education (MOE) National Research Foundation (NRF) Published version This work is supported by Singapore MOE project (MOE2019-T2-1-182). This research is supported by the Earth Observatory of Singapore via its funding from the National Research Foundation Singapore and Singapore Ministry of Education under the Research Center of Excellence initiative. This work comprises EOS contribution number 441. Ares Rosakis also wishes to acknowledge the support provided by NTU, through his Nanyang Visiting Professorship Appointment, in enabling this interdisciplinary collaboration. 2023-04-03T01:36:07Z 2023-04-03T01:36:07Z 2022 Journal Article Zeng, H., Wei, S. & Rosakis, A. (2022). A travel-time path calibration strategy for back-projection of large earthquakes and its application and validation through the segmented super-shear rupture imaging of the 2002 Mw 7.9 Denali earthquake. Journal of Geophysical Research: Solid Earth, 127(6). https://dx.doi.org/10.1029/2022JB024359 2169-9313 https://hdl.handle.net/10356/165584 10.1029/2022JB024359 2-s2.0-85132890485 6 127 en MOE2019-T2-1-182 Journal of Geophysical Research: Solid Earth © 2022 The Authors. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes. application/pdf |
| spellingShingle | Science::Geology Back Projection Denali Earthquake Zeng, Hongyu Wei, Shengji Rosakis, Ares A travel-time path calibration strategy for back-projection of large earthquakes and its application and validation through the segmented super-shear rupture imaging of the 2002 Mw 7.9 Denali earthquake |
| title | A travel-time path calibration strategy for back-projection of large earthquakes and its application and validation through the segmented super-shear rupture imaging of the 2002 Mw 7.9 Denali earthquake |
| title_full | A travel-time path calibration strategy for back-projection of large earthquakes and its application and validation through the segmented super-shear rupture imaging of the 2002 Mw 7.9 Denali earthquake |
| title_fullStr | A travel-time path calibration strategy for back-projection of large earthquakes and its application and validation through the segmented super-shear rupture imaging of the 2002 Mw 7.9 Denali earthquake |
| title_full_unstemmed | A travel-time path calibration strategy for back-projection of large earthquakes and its application and validation through the segmented super-shear rupture imaging of the 2002 Mw 7.9 Denali earthquake |
| title_short | A travel-time path calibration strategy for back-projection of large earthquakes and its application and validation through the segmented super-shear rupture imaging of the 2002 Mw 7.9 Denali earthquake |
| title_sort | travel time path calibration strategy for back projection of large earthquakes and its application and validation through the segmented super shear rupture imaging of the 2002 mw 7 9 denali earthquake |
| topic | Science::Geology Back Projection Denali Earthquake |
| url | https://hdl.handle.net/10356/165584 |
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